Repeating of glass-cracking:

Procedure:

For Schlieren experiments, we used the Schlieren projector in lab.  The projector is designed to work as shown in Figure~\ref{fig:schlieren-photography}.

\begin{figure}[h!]
\centering
\includegraphics[width=6.5in]{schlieren-photography}
\caption{Diagram of a Schlieren Photography system}
\label{fig:schlieren-photography}
\end{figure}

For our experiments, we suspended a piece of glass within the Schlieren field of view with a ringstand clamp.  The glass was held from one side.  We then heated the glass with the heat gun.  Once the temperature of the glass, as measured with a thermocouple, stopped increasing, we removed the heat gun and dropped a droplet of water from a titration valve onto the glass.  The specific used materials are listed in Table~\ref{fig:MaterialsHeatShockSchlieren}.


\begin{tabular}{l|c|c|c}
\emph{Item}
&	\emph{Manufacturer}
&	\emph{Model}
&	\emph{S/N} \\
Hot Air Gun
& 	Accupro
&	1500 Watt 
&	n/a \\
Tripod (for Phantom Camera)
& 	Manfrotto
& 	3021BPRO
& 	n/a \\
Eyedropper
& 	n/a
& 	n/a
& 	n/a \\
Metal Lab Ring Stand with Horizontal Clamp
& 	n/a 
&	n/a
& 	n/a \\
Water
& 	n/a
& 	Tap
& 	n/a\\
Schlieren Imager
&	n/a
&	Edgerton Center
&	n/a\\
Schlieren Imager Lamp
&	DNR
&	DNR
&	DNR\\
Schlieren Video Camera
&	DNR
&	NTSC Color Video Camera
&	DNR\\
\end{tabular}
\end{center}
\label{fig:MaterialsHeatShockSchlieren}
\end{table}




